Okey, most addons in KODI are based on python code. Which often is the same independent of hardware architecture. Then there is the binary addons, like support for different audio formats, image formats etc.
So let’s say, inorder to have support for audio format.flac decode or encode, are both needing processor unique instruction inorder to optimize it enough to do it realtime.
Same goes for the libretto.compabillity addon for Kodi as well as for all the cores(emulators).
This is what I’ve understood happened between 18 and 19, a lot of edge trimming in the KODI-code tree, I mean whole hardware platforms were “let go officially”, and I’m certain I read somewhere that Libretto.compabillity addon was Kodirelated enough, but the libretro-cores are outside of actual Kodi code. There for not in the official binary-repo.
So when Sam cloned the binary-addon-repo from Kodi to Osmc, the was two game related game-addons, the rest had been moved out of official repository. Eg. There is still a working solution, just not part of KODI code tree. Kodi-game is a bin-repo that I have worked some time to get ruining on Vero, but having a 30+h build time every time Kodi updates, is annoying. Since all I’ve managed so far is built 80-ish cores. But just because they build doesn’t mean they work on the Vero fresh out of the compiler, some of them need configurations, bios files and other stuff.
So I would have to test 80 cores, test if they work with a rom file, if not what is in the debug log, can it be fixed, try again. It’s a time consuming workload to get a bunch of working emulators. Tried to enlist the help of a few users here, but the lack of response and the reminder of Zacks build bot repo. Made my work less important, Osmc is a MediaCenter first, emulators are fine, but not a priority on a sbc.
So in short Zack repo is the best choice right now. No compile needed, any depends are fixed right out of the box.
Ps. Plus with Zacks other repo you get help with archives, bios management and IAGL, Which can download roms, metadata like covers and screenshots from archive.org, to play wthose games with the emulator-cores you have installed in KODI via builbot.